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Water: California Toxics Rule

The California Toxics Rule (CTR)

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

EPA-823-F-97-008; August 1997

Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California


The U.S. Environmental Protection Agency (U.S. EPA) is proposing water quality criteria for priority toxic pollutants for California inland surface waters, enclosed bays, and estuaries. These federally promulgated criteria, when finalized, together with State-adopted designated uses, will create water quality standards for those California waters. This rule will satisfy Clean Water Act (CWA) requirements and fill the need for water quality standards for priority toxic pollutants to protect public health and the environment. U.S. EPA and the State of California are working to restore standards to California waters: U.S. EPA is now proposing water quality criteria, and the State will soon be proposing implementation procedures to ensure that the resulting water quality standards will be appropriately and consistently applied throughout the State. U.S. EPA will be holding two public hearings: one in San Francisco on September 17, 1997 at the U.S. EPA Region 9 Office, 75 Hawthorne Street, at 1:00 p.m., and one in Los Angeles on September 18, 1997 at the Los Angeles Department of Water and Power, 111 N. Hope Street (across from the Los Angeles Music Center), at 1:00 p.m. Public comments must be submitted on or before Friday, September 26, 1997 to Diane Frankel, U.S. EPA Region 9 (WTR-5), 75 Hawthorne Street, San Francisco, CA 94105.

Federal Authority

Under the CWA, states have the primary responsibility for developing and implementing water quality standards for priority toxic pollutants. The CWA gives U.S. EPA the authority to promulgate for a state when necessary to meet the requirements of the CWA. Although California has made important progress toward satisfying CWA requirements, it is the only state in the nation for which the CWA requirement to adopt numeric priority toxic pollutant criteria remains substantially unimplemented. U.S. EPA has determined that this rule is an important component of California's water quality control program which is necessary to further the control of toxic pollutants in the State's inland surface waters, enclosed bays and estuaries.


The California State Water Resources Control Board adopted in April 1991 two water quality control plans: the Inland Surface Water Plan and the Enclosed Bays and Estuaries Plan. These two statewide plans included numeric water quality criteria for priority toxic pollutants. However, these plans were rescinded when a lawsuit brought by several dischargers successfully challenged how the plans were adopted. Since 1994, California has been without water quality standards for most priority pollutants for inland surface waters, enclosed bays and estuaries as required by Section 303(c)(2)(B) of the CWA.

These federal criteria together with State-adopted designated uses (found in the nine Regional Water Quality Control Board Basin Plans) will create water quality standards which are used to write permits for point sources such as industrial and municipal wastewater outfalls. Other uses include setting goals for Superfund cleanups and assessing "Best Management Practices" (BMPs) for nonpoint source and wet weather discharges such as agricultural and urban runoff. BMPs are practices which are implemented to reduce pollution caused by runoff. Without standards, both point and nonpoint source pollutant reduction programs lose enforceability and direction.

Today's Action

U.S. EPA and the State are working to restore integrity to the State's water program: the U.S. EPA is now proposing water quality criteria for priority toxic pollutants for inland surface waters, enclosed bays and estuaries and an authorizing compliance schedule provision. The State will soon be proposing procedures for implementing the resulting water quality standards based on the federal criteria. The State retains control for implementing the criteria and resulting water quality standards. These federal criteria will be in effect until the State's own rulemaking is complete. After the State adopts implementation procedures, it plans to begin the process of readopting comprehensive statewide water quality control plans for inland surface waters, enclosed bays and estuaries. These plans will include State water quality criteria for priority toxic pollutants. After such plans are adopted, U.S. EPA will review and approve as appropriate, the State's plans. The U.S. EPA intends to stay the CTR when State criteria are developed and approved.

Economic Analysis (EA) - Costs and Benefits

U.S. EPA's proposed ambient water quality criteria do not establish any requirements directly applicable to regulated entities. Ambient water quality standards will be created from federal criteria and State-adopted designated uses. When steps are taken to implement these resulting water quality standards, economic effects may be felt on some dischargers.

U.S. EPA attempted to estimate the costs and benefits associated with implementation of the resulting water quality standards. It is important to note that large uncertainties associated with both the costs and benefits exist: many benefits are excluded because they could not be either quantified or monetized. Costs are estimated assuming the State would use certain implementation procedures; once the State adopts implementation procedures, costs of implementation can be estimated with more certainty.

The Economic Analysis (EA) contains estimates of costs to point sources such as publicly owned treatment works (POTWs) and industrial facilities that discharge to inland surface waters or enclosed bays and estuaries in California. The study only analyzes those point sources that are typically subject to water quality-based effluent limits (WQBELs) calculated using CTR-based water quality standards. The benefit estimates include only those that may occur as a result of loadings reductions from point sources that are typically subject to numeric WQBELs.

Results: Costs: U.S. EPA estimated the incremental costs and benefits using two models which used different baselines. The first model uses a baseline that results in no incremental impacts. Under this baseline, it is assumed that, in the absence of this rule, the State would rely on regional narrative toxicity standards to establish numeric WQBELs. The limits could be based on the same information upon which the CTR criteria are based. Under this scenario, no impacts would be attributed to implementation of CTR-based standards since it is assumed that the State would implement roughly equivalent WQBELs.

The second model uses a baseline that assumes that, in the absence of the CTR and its subsequent implementation, current permit limits and current effluent concentrations would remain constant in the future. This model generally uses a baseline of current permit limits to develop a high cost scenario and current effluent concentrations to develop a low cost scenario.

Using this second model, EPA estimated a range of annual costs of $14.9 million (low scenario) to $86.6 million (high scenario). EPA believes that the actual costs will approach the low-end of the cost range. Costs are unlikely to reach the high-end of the range because State implementing authorities are likely to choose implementation options that provide flexibility to point source dischargers. Cost estimates may be overstated, as the analysis tends to use conservative assumptions to calculate CTR-based permit limits and baseline loadings.

Results: Benefits:

Benefits are categorized as either use benefits or passive (nonuse) benefits depending on whether they involve some source of direct use, or contact with, the resource. The most prominent use benefits are those related to recreational fishing, boating, and swimming. Another use benefit of significance is human health risk reduction. Human health risk reduction can be realized through actions that reduce human exposure to contaminants such as through the consumption of fish containing elevated levels of pollutants. Passive use benefits are those improvements in environmental quality that are valued by individuals apart from any use of the resource in question.

Total monetized annual benefits (using Model 2) are estimated in the range of $1.5 million to $51.7 million. By category, annual benefits are $0 to $5.3 million for avoided cancer risk, $0.6 to $10.1 million for recreational angling, and $0.9 to $36.3 million for passive use benefits.

Many categories of benefits are not quantified or monetized, such as: improvements in water related (in-stream/near stream) recreation apart from fishing, such as boating, swimming, and picnicking; improvements in human health resulting from reduction of non-cancer risks; and improvements in consumptive and nonconsumptive land-based recreation such as hunting and wildlife observation. Therefore, actual benefits are expected to be significantly larger than the estimate of monetized benefits.


A comparison of estimated annualized costs to benefits shows that the benefits range overlaps the cost range, and the values are similar in magnitude. Annualized costs range from $14.9 to $86.6 million, and annualized monetized benefits range from $1.5 to $51.7 million. However, since the U.S. EPA used a number of assumptions that may have overstated costs and omitted benefits categories, benefits and costs are likely to be more commensurate than indicated here.

For More Information

Call or write: for the EA, Matt Mitchell, 415 744-2007; for the CTR, Diane Frankel, 415 744-1984; U.S. EPA, 75 Hawthorne Street (WTR-5), San Francisco, CA 94105. The entire Federal Register notice (published on August 5, 1997) may be accessed at http://www.epa.gov/EPA-WATER/1997/August/Day-05/. Additionally, the EA may be read online or downloaded from this website. (PDF Format, 520K)

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